diff --git a/openbsc/src/gprs/gprs_bssgp.c b/openbsc/src/gprs/gprs_bssgp.c
index f27e3a7..0ec873c 100644
--- a/openbsc/src/gprs/gprs_bssgp.c
+++ b/openbsc/src/gprs/gprs_bssgp.c
@@ -734,7 +734,7 @@
 		llc_pdu_tlv[1] = msg_len >> 8;
 		llc_pdu_tlv[2] = msg_len & 0xff;
 	} else {
-		llc_pdu_tlv[1] = msg_len & 0x3f;
+		llc_pdu_tlv[1] = msg_len & 0x7f;
 		llc_pdu_tlv[1] |= 0x80;
 	}